1. The Field of the Invention
The present invention relates to a liquid ejecting apparatuses. More specifically, the present invention relates to a liquid ejecting apparatus having a small-sized carriage for carrying a recording head.
2. The Relevant Technology
Several ink printers have been developed, each having a liquid ejecting apparatus, including a head that ejects liquid, such as ink. The liquid ink is usually contained in an ink cartridge, within the liquid ejecting head.
Currently, such ink printers for office use and commercial use consume large amounts of ink because their printing frequencies are high. In such high volume printers, it is necessary for those printers to have large-capacity ink cartridges. In printers having an on-carriage type printer, or a configuration wherein the carriage includes a cartridge holder for carrying ink cartridges, difficulties arise when the printer requires large-capacity ink cartridges. In order to accommodate the larger ink cartridges, the carriage is increased in size, which also increases the load applied on the printer while moving the carriage.
FIG. 6 shows a carriage 1 carrying on-carriage type ink cartridges of the variety described above. As illustrated, a plurality of ink cartridges 2 containing different color inks are mounted on the carriage 1. In order to accommodate the large ink cartridges 2, the carriage 1 has a large size. As a result, the carriage 1, also has a large weight, and is generally not suitable for use in small-sized liquid ejecting apparatuses, such as the compact printers which are popular today.
One common approach used to solve this problem is an off-carriage type printer, where the ink cartridges are disposed away from the carriage. In the off-carriage type printer, it is necessary to move the different color inks from respective ink tanks arranged in a body of the printer to the carriage, or more specifically, to a series of subtanks on the carriage. Additionally, the carriage must remain movable in a main scanning direction.
It is therefore necessary to use a thick or multilayer tube as a feed pipe in order to prevent evaporation of water from each ink supply and to arrange a plurality of thick or multilayer tubes corresponding to the different color inks.
For example, Japanese Patent Application Number JP-A-9-11498, as illustrated in FIG. 7, discloses an ink jet recording apparatus having a carriage 3 carrying a plurality of small-sized subtanks (not shown). In this apparatus, each highly concentrated color ink is diluted in a body of the apparatus and is then supplied to the corresponding subtank on the carriage every printing. Additionally, the described ink jet recording apparatus takes countermeasures to reduce the evaporation of water from each supplied ink.
Disadvantageously, however, since the apparatus has a structure in which a plurality of ink cartridges are arranged in the apparatus body, each color ink is diluted in the apparatus body, and the diluted ink is then supplied to the corresponding subtank on the carriage. Thus it is necessary to connect a plurality of tubes 4 to the carriage 3 moved in the main scanning direction in a manner similar to the off-carriage type.
Unfortunately, however, in many small-sized liquid ejecting apparatuses, the power of a driving unit which moves the carriage is limited. Accordingly, the structure in which a plurality of or many tubes are connected to a carriage and the carriage is moved in the main scanning direction has a disadvantage in that the resistance to the movement is higher as the number of tubes is larger. Thus, it is difficult for the driving unit to move the carriage in the main scanning direction.